[Bug]Libre office 4.1.4.2 Execption com.sun.star.lang.IllegalArgumentException 665 adding reference

I am working on a report containing a fair amount of references already which where added without any problems. Problems started when I added a url by using the "Add entry manually" option in Mendeley Desktop. Then I tried to reference this website by using the Insert Citation button of the Mendeley extension in Libre Office. The extension added a {Formatting Citation} and crashed with I think the error: (I am not sure about this one) Error: An exception occurred Type: com.sun.star.lang.IllegalArgumentException Message: . At line: 759 The {Formatting Citation} tag remained in the document, and when pressing the refresh button this error is showed: Error: An exception occurred Type: com.sun.star.lang.IllegalArgumentException Message: . At line: 665 Running on Windows XP 64bit SP2